Mission control has lost contact with the ESA’s ExoMars lander

As it would seem, the Great Galactic Ghoul is still hungry, and the ESA’s ExoMars Schiaparelli lander might have been its next meal. Just moments before the lander was to touchdown on Martian soil, mission control lost contact with it, and it isn’t looking good for the surface mission. Schiaparelli departed cleanly from TGO (the Trace Gas Orbiter), which is doing fine, with all systems nominal and reporting back as expected. So was the lander, until everything went pear-shaped.

Things were going fine up until about five minutes into the six-minute descent from a low orbit to the Martian surface. The front and rear heat shields came off as planned, and the retro thrusters fired, but only for 3 or 4 seconds, much shorter than the expected 30-second burn. Then the communications feed cut out. Mission control still hasn’t reestablished contact with the lander.

Planned Schiaparelli descent sequence. Credit: ESA/ATG medialab

There are multiple possible explanations for what could have gone wrong. The parachute may have detached either too early or too late, but it was probably too early. Too early would leave the craft vulnerable to touching down somewhere unplanned, maybe somewhere dangerous. Too late and the lander dashes itself against the ground at damaging speeds. Mission scientists are doing the data processing, and telemetry should be able to say how fast Schiaparelli was going when it touched the ground. “We should be able to detect whether there was a hard signal of touchdown,” said ESA‘s head of solar and planetary missions Andrea Accomazzo.

If the probe is still in working order, it will have somewhere between three and 10 days of battery power, which means it will have multiple opportunities to make a communication link with one of three satellites currently orbiting Mars: the TGO, Mars Express, and the Mars Reconnaissance Orbiter.

The October 20 ExoMars press conference. Credit: ESA

Happily, NASA’s Opportunity rover was hanging out 15 kilometers from Schiaparelli’s planned landing zone. It was initially supposed to be taking a bunch of pictures of the lander as it descended. Whether that worked will depend on the exact trajectory Schiaparelli followed.

The lander was supposed to touch down in the middle of a huge hematite deposit, because hematite on Earth forms where there’s water, and water is important to life. The “exo” part of ExoMars is short for “exobiology” — this mission is designed to peer closely at Mars for signs of life, whether past or present. Scientists believe that life currently present on Mars would produce methane, which their orbiting trace gas detector could pick up.

If Schiaparelli survives its landing, it will be the first non-NASA spacecraft to operate successfully on Mars for more than a few seconds. The “Great Galactic Ghoul” I mentioned at the top is a bit of gallows humor about the apparently endless hunger the Red Planet has for spacecraft: imagine a huge, hungry monster looming over Mars, waiting to snatch up likely spacecraft. The trip to Mars is tough, and it claims a lot of spacecraft. Only further observation can tell us what happened in the last few seconds of Schiaparelli’s descent.